Applicant in his U.S. Pat. No. 3,871,812 disclosed a foam extrusion die assembly which facilitates obtaining the proper die orifice shape for a desired profile of an extruded product, e.g., foam boards, planks and logs. Applicant therein provided a die body to which were fastened two spaced, adjustable die lip members that extended axially outwardly from the face of the die body at the discharge end thereof. The die lip members had arcuate outer faces which together defined an elongated, axially outwardly extending, arcuate die orifice through which foaming material could move both laterally and axially outwardly relative to the lip members. The lip members were mounted on the die body for slight movement by a plurality of fasteners extending through oversized bores both in the body and lip members and were manipulable such that the die orifice may be opened or closed at the center thereof to correct the shape of the orifice to obtain the desired profile of the extruded product.
In his U.S. Pat. No. 4,201,534, applicant disclosed an improved foam extrusion die assembly. In this assembly, the lip members were mounted on the die body by centrally located screws for slight movement while toe and heel clamp assemblies fastened to the die body biased the lip members against the face of the die body for continuous sealing line contact with the die body face to preclude the undesirable passage of foaming material between the die body and lip members. Adjusting screws positioned forwardly and rearwardly of the centrally located screws engaged the outermost sides of the lip members and could be adjusted to obtain the desired profile of the extruded product.
Applicant more recently has made a further improvement in the extrusion die assembly disclosed in his U.S. Pat. No. 4,201,534. In this improvement, a small full width semicircular bead was provided on the inner or sealing face of each lip member to provide a somewhat better continuous line seal with the die body face and further to facilitate pivotal adjustment of the lip members.